When Bill McDonough rides the commuter rail into Boston, a 40-minute trip from Hanson, the 55-year-old often offers his seat to others — even younger passengers.

Super polite? No. He’s part of an anti-sitting movement that’s gaining followers as evidence continues to build that what was once considered a benign pastime — sitting for extended periods — can actually shorten your lifespan, increase the risk of cardiovascular problems and diabetes, and contribute to obesity later in life.

“I get annoyed when I have to sit down for a phone call or take notes,” said McDonough, the owner of Scribendi, an advertising company in Hanson.

The don’t-take-a-seat trend, which has already made its way into offices, where workers are braving colleagues’ ridicule as they stand, walk or even cycle at special desks, is now infiltrating other spaces. It can be seen at restaurants, where some patrons would rather stand at the bar than grab a table; at meetings, where anti-sitters discreetly rise from their chairs, as eager to avoid detection as a scofflaw texting during a show; and at parties, where those eager to avoid chair time help the host serve — and not just to be helpful.

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DINA RUDICK/GLOBE STAFF

Jay Ciruolo works at his standing desk at CarGurus in Cambridge.

In some circles, friends and relatives engage in what Sara Rimer, a media relations specialist at Boston University, only somewhat jokingly calls “competitive non-sitting.”

When she and her sisters get together, Rimer said, “I would notice my oldest sister seemed to be making a habit of standing while my middle sister and I were sitting. So then the two of us starting standing up, too.”

Rimer added she was recently shamed by a friend when the two were out, at Daedalus in Harvard Square, and she suggested they get a table since the bar was packed. “But sitting’s bad for you,” her pal countered.

Fitness guru Gretchen Reynolds says she’s hearing about people who have started standing even while they watch television. “It seems like such an easy approach to health, as opposed to feeling like you have to go out and run for an hour,” said Reynolds, the author of “The First 20 Minutes: Surprising Science Reveals How We Can: Exercise Better, Train Smarter, Live Longer.”

“I’m standing right now,” Reynolds said during a phone interview.

In October, two newly released studies found yet more evidence that the activity, or inactivity as the case may be, is unhealthy. In October, the British Journal of Sports Medicine
reported that every hour a person sits watching TV takes 22 minutes off his or her life. “TV viewing time may be associated with a loss of life that is comparable to other major chronic disease risk factors such as physical inactivity and obesity,” the researchers reported.

Also last month, Diabetologia
, a diabetes journal, published a study showing that sedentary time is associated with increased risk of diabetes, cardiovascular disease, and mortality in general.

Those studies follow numerous others with bad news for the couch or office potato set. The research findings have triggered a new malady known as “sitting disease,” and an onslaught of jokey headlines. Businessweek commanded readers to “Kill Your Desk Chair — and Start Standing.” The headline on a Forbes piece looking at the fast-growing standing desk segment read: “Get Up, Stand Up, For Your Life: Can Standing Desks Fight Sitting Disease?”

“When I’m at conferences I’ll go stand in the back of the room,” said Carole Pelissey, a school psychologist from Jamaica Plain. Sometimes she even does a squat with her back against the wall, but only if no one’s looking. “I don’t want to put it in people’s faces,” she says of her attempt to keep her blood flowing.

Gregory Cloutier, the project manager for Northeastern University’s Human Performance and Exercise Science Laboratory, also tries to be subtle about his non-sitting habit. Not when he’s at work, where a focus on exercise is the norm, but in his home life. At parties, he said, he’s the first guy offering to pass hors d’oeuvres or help clean up. “I’m not obsessed,” he said, “but I want to move.”

When Jay Ciruolo started his new job, at CarGurus, in Cambridge, he wanted a standing desk, but he didn’t want to call attention to himself with a silly-looking setup. “I didn’t want people to think, ‘Look at this guy being all health conscious,’ ” said Ciruolo, 28. “And those desks are really expensive.”

But eager to reverse sitting-induced weight gain and neck pain, Ciruolo bought bed risers at Bed, Bath & Beyond, and has lost about 12 pounds in under two years. His neck pain is also gone, although his colleagues’ good-natured ribbing remains, especially since Ciruolo wears headphones while he works, and is positioned near the front door. “Are you spinning records?” people ask. Or: “Is this the CarGurus control center?”

Perhaps nothing says trend like an on-line tool. Ergotron, a maker of sit-stand desks and other furniture, has just introduced a sitting-time calculator that computes a user’s risk for “sitting disease,” a term that the firm acknowledges the “medical community does not recognize . . . as a diagnosable disease at this time.” Ergotron’s JustStand.org site even carries statistics about sitting. For example: “Men who were inactive and sat over six hours daily were 48 percent more likely to die [during the study period] than their standing counterparts,” reads a blurb from a 2010 American Cancer Society study on the site.

Sherry Pagoto, an associate professor of medicine at the University of Massachusetts Medical School, in Worcester, has read so many studies on risks of being sedentary that she’s started to feel guilty when she allows herself to sit. “I’ve started to feel like I’m doing something unhealthy,” she said.

Pagoto exercises regularly, but with studies showing that gym time cannot undo hours of sitting, she said she’s starting to question “how healthy I really am.”

Toward that end, she and like-minded colleagues have begun tweeting hourly to encourage each other to rise and do a plank or some other form of quick exercise. Sometimes unsuspecting people come into her office and find her in the core-strengthening move. “They either do it with me,” she said, “or they think I’m out of my mind.”

Of course, many people who work on their feet all day would welcome the opportunity to sit down. And prolonged standing can also lead to health problems, according to
Alan Hedge
at Cornell University, where he is a professor in the Department of Design and Environmental Analysis and director of the school’s Human Factors and Ergonomics Laboratory. These include an increased risk of varicose veins, and, in people with heart disease, stroke.

“In our field studies of sit-stand workstations we have found little evidence of widespread benefits, and users only stand for very short-periods — 15 minutes or less total per day,” Hedge said. And other research has found that treadmill or bicycle workstations decrease computer work performance.

The ideal scenario, Hedge said, is that people should sit while doing computer work, but rise every 20 minutes throughout the day and move around for a couple of minutes.

But at CarGurus, Ciruolo has a different set of concerns: footwear. “There aren’t a lot of options for shoes that are good for standing in all day that go with anything else.”